(Amendment No. 3)
Check the appropriate box to designate the rule pursuant to
which this Schedule is filed:
* The remainder of this cover page shall
be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for
any subsequent amendment containing information which would alter disclosures provided in a prior cover page.
The information required in the remainder of this cover page
shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”)
or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however,
see the Notes).
CUSIP
No. 002120103
|
13G/A
|
Page
2 of 14 Pages
|
1
|
NAME
OF REPORTING PERSON
S.S.
OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY)
Viking Global Investors LP
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a)
☐
(b) ☒
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware
|
NUMBER
OF
SHARES
BENEFICIALLY
OWNED
BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE
VOTING POWER
0
|
6
|
SHARED
VOTING POWER
0*
|
7
|
SOLE
DISPOSITIVE POWER
0
|
8
|
SHARED
DISPOSITIVE POWER
0*
|
9
|
AGGREGATE
AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ☐
|
11
|
PERCENT
OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0%*
|
12
|
TYPE
OF REPORTING PERSON*
PN
|
|
|
|
|
|
|
*
See Item 4
CUSIP
No. 002120103
|
13G/A
|
Page
3 of 14 Pages
|
1
|
NAME
OF REPORTING PERSON
S.S.
OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY)
Viking
Global Opportunities GP LLC
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a)
☐
(b) ☒
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware
|
NUMBER
OF
SHARES
BENEFICIALLY
OWNED
BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE
VOTING POWER
0
|
6
|
SHARED
VOTING POWER
0*
|
7
|
SOLE
DISPOSITIVE POWER
0
|
8
|
SHARED
DISPOSITIVE POWER
0*
|
9
|
AGGREGATE
AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0*
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ☐
|
11
|
PERCENT
OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0%*
|
12
|
TYPE
OF REPORTING PERSON*
OO
|
|
|
|
|
|
|
*
See Item 4
CUSIP
No. 002120103
|
13G/A
|
Page
4 of 14 Pages
|
1
|
NAME
OF REPORTING PERSON
S.S.
OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY)
Viking Global Opportunities Portfolio GP LLC
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a)
☐
(b) ☒
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware
|
NUMBER
OF
SHARES
BENEFICIALLY
OWNED
BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE
VOTING POWER
0
|
6
|
SHARED
VOTING POWER
0*
|
7
|
SOLE
DISPOSITIVE POWER
0
|
8
|
SHARED
DISPOSITIVE POWER
0*
|
9
|
AGGREGATE
AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0*
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ☐
|
11
|
PERCENT
OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0%*
|
12
|
TYPE
OF REPORTING PERSON*
OO
|
|
|
|
|
|
|
*
See Item 4
CUSIP
No. 002120103
|
13G/A
|
Page
5 of 14 Pages
|
1
|
NAME
OF REPORTING PERSON
I.R.S.
IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY)
Viking
Global Opportunities Illiquid Investments Sub-Master LP
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a)
☐
(b)
☒
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
Cayman Islands
|
NUMBER
OF
SHARES
BENEFICIALLY
OWNED
BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE
VOTING POWER
0
|
6
|
SHARED
VOTING POWER
0*
|
7
|
SOLE
DISPOSITIVE POWER
0
|
8
|
SHARED
DISPOSITIVE POWER
0*
|
9
|
AGGREGATE
AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0*
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ☐
|
11
|
PERCENT
OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0%*
|
12
|
TYPE
OF REPORTING PERSON*
PN
|
|
|
|
|
|
|
*
See Item 4
CUSIP
No. 002120103
|
13G/A
|
Page
6 of 14 Pages
|
1
|
NAME
OF REPORTING PERSON
I.R.S.
IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY)
O.
Andreas Halvorsen
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a)
☐
(b) ☒
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
Norway
|
NUMBER
OF
SHARES
BENEFICIALLY
OWNED
BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE
VOTING POWER
0
|
6
|
SHARED
VOTING POWER
0*
|
7
|
SOLE
DISPOSITIVE POWER
0
|
8
|
SHARED
DISPOSITIVE POWER
0*
|
9
|
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0*
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ☐
|
11
|
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0%*
|
12
|
TYPE
OF REPORTING PERSON*
IN
|
|
|
|
|
|
|
*
See Item 4
CUSIP
No. 002120103
|
13G/A
|
Page
7 of 14 Pages
|
1
|
NAME
OF REPORTING PERSON
I.R.S.
IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY)
David
C. Ott
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a)
☐
(b) ☒
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
United States
|
NUMBER
OF
SHARES
BENEFICIALLY
OWNED
BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE
VOTING POWER
0
|
6
|
SHARED
VOTING POWER
0*
|
7
|
SOLE
DISPOSITIVE POWER
0
|
8
|
SHARED
DISPOSITIVE POWER
0*
|
9
|
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0*
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ☐
|
11
|
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0%*
|
12
|
TYPE
OF REPORTING PERSON*
IN
|
|
|
|
|
|
|
*
See Item 4
CUSIP
No. 002120103
|
13G/A
|
Page
8 of 14 Pages
|
1
|
NAME
OF REPORTING PERSON
I.R.S.
IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY)
Rose
S. Shabet
|
2
|
CHECK
THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a)
☐
(b) ☒
|
3
|
SEC USE ONLY
|
4
|
CITIZENSHIP OR PLACE OF ORGANIZATION
United States
|
NUMBER
OF
SHARES
BENEFICIALLY
OWNED
BY
EACH
REPORTING
PERSON
WITH
|
5
|
SOLE VOTING POWER
0
|
6
|
SHARED
VOTING POWER
0*
|
7
|
SOLE DISPOSITIVE POWER
0
|
8
|
SHARED
DISPOSITIVE POWER
0*
|
9
|
AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
0*
|
10
|
CHECK
BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* ☐
|
11
|
PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
0%*
|
12
|
TYPE
OF REPORTING PERSON*
IN
|
|
|
|
|
|
|
*
See Item 4
CUSIP
No. 002120103
|
13G/A
|
Page
9 of 14 Pages
|
|
Item
1(a).
|
Name
of Issuer:
|
aTyr
Pharma, Inc.
|
Item
1(b).
|
Address
of Issuer’s Principal Executive Offices:
|
3545
John Hopkins Court, Suite #250
San
Diego, California 92121
|
Item
2(a).
|
Name
of Person Filing:
|
Viking
Global Investors LP (“VGI”),
Viking
Global Opportunities GP LLC (“Opportunities GP”),
Viking
Global Opportunities Portfolio GP LLC (“Opportunities Portfolio GP”),
Viking
Global Opportunities Illiquid Investments Sub-Master LP ("VGOP"),
O.
Andreas Halvorsen, David C. Ott and Rose S. Shabet (collectively, the "Reporting Persons")
|
Items
2(b).
|
Address
of Principal Business Office or, if none, Residence:
|
The
business address of each of the Reporting Persons is: 55 Railroad Avenue, Greenwich, Connecticut 06830.
VGI
is a Delaware limited partnership; Opportunities GP and Opportunities Portfolio GP are Delaware limited liability companies; VGOP
is a Cayman Islands exempted limited partnership; O. Andreas Halvorsen is a citizen of Norway; and David C. Ott and Rose S. Shabet
are citizens of the United States.
|
Item
2(d).
|
Titles
of Classes of Securities:
|
Common
stock, par value $0.001 per share (“Common Stock”)
|
Item
2(e).
|
CUSIP
NUMBER: 002120103
|
|
Item
3.
|
If
This Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or (c), Check Whether the Person Filing is a:
|
|
(a)
|
☐ Broker or dealer registered under Section 15 of the Exchange Act
|
|
(b)
|
☐ Bank as defined in Section 3(a)(6) of the Exchange Act
|
|
(c)
|
☐ Insurance company as defined in Section 3(a)(19) of the Exchange Act
|
|
(d)
|
☐ Investment company registered under Section 8 of the Investment
Company Act of 1940
|
CUSIP
No. 002120103
|
13G/A
|
Page
10 of 14 Pages
|
|
(e)
|
☐ Investment Adviser registered under Section 203 of the Investment Advisers Act of 1940:
see Rule 13d-1(b)(1)(ii)(E)
|
|
(f)
|
☐ Employee Benefit Plan, Pension Fund which is subject to the provisions of the Employee
Retirement Income Security Act of 1974 or Endowment Fund; see Rule 13d-1(b)(1)(ii)(F)
|
|
(g)
|
☐ Parent holding company, in accordance with Rule 13d-1(b)(1)(ii)(G).
|
|
(h)
|
☐ Savings Association as defined in Section 3(b) of the Federal Deposit Insurance Act.
|
|
(i)
|
☐ Church Plan that is excluded from the definition of an investment company under Section
3(c)(14) of the Investment Company Act of 1940.
|
|
(j)
|
☐ Non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J). If filing as a
non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J), please specify the
type of institution:
|
|
(k)
|
☐ Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
|
A.
VGI
|
(a)
|
Amount
beneficially owned: 0
|
|
(c)
|
Number
of shares as to which such person has:
|
|
(i)
|
Sole
power to vote or to direct the vote: 0
|
|
(ii)
|
Shared
power to vote or to direct the vote: 0
|
|
(iii)
|
Sole
power to dispose or to direct the disposition of: 0
|
|
(iv)
|
Shared
power to dispose or to direct the disposition of: 0
|
VGI
provides managerial services to VGOP. VGI has the authority to dispose of and vote the shares of Common Stock.
Based
on Rule 13d-3 of the Securities Exchange Act of 1934, as amended (the "Act"), VGI may be deemed to beneficially own
the shares of Common Stock directly held by VGOP. VGI does not directly own any shares of Common Stock.
B.
Opportunities GP
|
(a)
|
Amount
beneficially owned: 0
|
CUSIP
No. 002120103
|
13G/A
|
Page
11 of 14 Pages
|
|
(c)
|
Number
of shares as to which such person has:
|
|
(i)
|
Sole
power to vote or to direct the vote: 0
|
|
(ii)
|
Shared
power to vote or to direct the vote: 0
|
|
(iii)
|
Sole
power to dispose or to direct the disposition of: 0
|
|
(iv)
|
Shared
power to dispose or to direct the disposition of: 0
|
Opportunities
GP serves as the sole member of Opportunities Portfolio GP and has the authority to dispose of and vote the shares of Common Stock
controlled by Opportunities Portfolio GP, which consists of the shares of Common Stock directly held by VGOP. Opportunities GP
does not directly own any shares of Common Stock.
Based
on Rule 13d-3 of the Act, Opportunities GP may be deemed to beneficially own the shares of Common Stock controlled by Opportunities
Portfolio GP, which consists of the shares of Common Stock directly held by VGOP.
C.
Opportunities Portfolio GP
|
(a)
|
Amount
beneficially owned: 0
|
|
(c)
|
Number
of shares as to which such person has:
|
|
(i)
|
Sole
power to vote or to direct the vote: 0
|
|
(ii)
|
Shared
power to vote or to direct the vote: 0
|
|
(iii)
|
Sole
power to dispose or to direct the disposition of: 0
|
|
(iv)
|
Shared
power to dispose or to direct the disposition of: 0
|
Opportunities
Portfolio GP serves as the general partner of VGOP and has the authority to dispose of and vote the shares of Common Stock directly
owned by VGOP. Opportunities Portfolio GP does not directly own any shares of Common Stock.
Based
on Rule 13d-3 of the Act, Opportunities Portfolio GP may be deemed to beneficially own the shares of Common Stock directly held
by VGOP.
D.
VGOP
|
(a)
|
Amount
beneficially owned: 0
|
|
(c)
|
Number
of shares as to which such person has:
|
CUSIP
No. 002120103
|
13G/A
|
Page
12 of 14 Pages
|
|
(i)
|
Sole
power to vote or to direct the vote: 0
|
|
(ii)
|
Shared
power to vote or to direct the vote: 0
|
|
(iii)
|
Sole
power to dispose or to direct the disposition of: 0
|
|
(iv)
|
Shared
power to dispose or to direct the disposition of: 0
|
VGOP
has the authority to dispose of and vote the shares of Common Stock directly owned by it, which power may be exercised by its
general partner, Opportunities Portfolio GP, and by VGI, an affiliate of Opportunities Portfolio GP, which provides managerial
services to VGOP.
Viking
Global Opportunities LP (a Delaware limited partnership) and Viking Global Opportunities III LP (a Cayman Islands exempted limited
partnership), through its investment in Viking Global Opportunities Intermediate L.P. (a Cayman Islands exempted limited partnership),
invest substantially all of their assets in Viking Global Opportunities Master LP (a Cayman Islands exempted limited partnership),
which in turn invests through VGOP.
E.
O. Andreas Halvorsen, David C. Ott and Rose S. Shabet
|
(a)
|
Amount
beneficially owned: 0
|
|
(c)
|
Number
of shares as to which such person has:
|
|
(i)
|
Sole
power to vote or to direct the vote: 0
|
|
(ii)
|
Shared
power to vote or to direct the vote: 0
|
|
(iii)
|
Sole
power to dispose or to direct the disposition of: 0
|
|
(iv)
|
Shared
power to dispose or to direct the disposition of: 0
|
Mr.
Halvorsen, Mr. Ott and Ms. Shabet, as Executive Committee Members of Viking Global Partners LLC, general partner of VGI and Opportunities
GP have shared authority to dispose of and vote the shares of Common Stock beneficially owned by VGI and Opportunities GP. None
of Mr. Halvorsen, Mr. Ott and Ms. Shabet directly owns any shares of Common Stock.
Based
on Rule 13d-3 of the Act, each may be deemed to beneficially own the shares of Common Stock directly held by VGOP.
|
Item
5.
|
Ownership
of Five Percent or Less of a Class.
|
If
this statement is being filed to report the fact that as of the date hereof the Reporting Persons have ceased to be the beneficial
owner of more than five percent of the class of securities, check the following [ X ].
|
Item
6.
|
Ownership
of More than Five Percent on Behalf of Another Person.
|
Yes,
see Item 4.
CUSIP
No. 002120103
|
13G/A
|
Page
13 of 14 Pages
|
|
Item
7.
|
Identification
and Classification of the Subsidiary Which Acquired the Security
|
Being
Reported on by the Parent Holding Company.
Not
applicable.
|
Item
8.
|
Identification
and Classification of Members of the Group.
|
Not
applicable.
|
Item
9.
|
Notice
of Dissolution of Group.
|
Not
applicable.
|
Item
10.
|
Certification.
(if filing pursuant to Rule 13d-1(c))
|
By
signing below each Reporting Person certifies that, to the best of its knowledge and belief, the securities referred to above
were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer
of the securities and were not acquired and not held in connection with or as a participant in any transaction having that purpose
or effect.
CUSIP
No. 002120103
|
13G/A
|
Page
14 of 14 Pages
|
SIGNATURES
After
reasonable inquiry and to the best of our knowledge and belief, the undersigned certify that the information set forth in this
statement is true, complete and correct.
Dated:
February 12, 2021
|
By:
|
/s/ Scott M. Hendler
|
|
Name:
Scott M. Hendler on behalf of O. Andreas Halvorsen (1)
|
|
By:
|
/s/ Scott M. Hendler
|
|
Name:
Scott M. Hendler on behalf of David C. Ott (2)
|
|
By:
|
/s/ Scott M. Hendler
|
|
Name:
Scott M. Hendler on behalf of Rose S. Shabet (3)
|
(1)
Scott M. Hendler is signing on behalf of O. Andreas Halvorsen, individually and as an Executive Committee Member of VIKING GLOBAL
PARTNERS LLC, on behalf of VIKING GLOBAL INVESTORS LP, and as an Executive Committee Member of VIKING GLOBAL OPPORTUNITIES GP
LLC, on behalf of itself and VIKING GLOBAL OPPORTUNITIES PORTFOLIO GP LLC and VIKING GLOBAL OPPORTUNITIES ILLIQUID INVESTMENTS
SUB-MASTER LP, pursuant to an authorization and designation letter dated February 9, 2021, which was previously filed with the
Commission as an exhibit to a Form 13G filed by Mr. Halvorsen on February 12, 2021 (SEC File No. 005-49737).
(2)
Scott M. Hendler is signing on behalf of David C. Ott, individually and as an Executive Committee Member of VIKING GLOBAL PARTNERS
LLC, on behalf of VIKING GLOBAL INVESTORS LP, and as an Executive Committee Member of VIKING GLOBAL OPPORTUNITIES GP LLC, on behalf
of itself and VIKING GLOBAL OPPORTUNITIES PORTFOLIO GP LLC and VIKING GLOBAL OPPORTUNITIES ILLIQUID INVESTMENTS SUB-MASTER LP,
pursuant to an authorization and designation letter dated February 9, 2021, which was previously filed with the Commission as
an exhibit to a Form 13G filed by Mr. Ott on February 12, 2021 (SEC File No. 005-49737).
(3)
Scott M. Hendler is signing on behalf of Rose S. Shabet, individually and as an Executive Committee Member of VIKING GLOBAL PARTNERS
LLC, on behalf of VIKING GLOBAL INVESTORS LP, and as an Executive Committee Member of VIKING GLOBAL OPPORTUNITIES GP LLC, on behalf
of itself and VIKING GLOBAL OPPORTUNITIES PORTFOLIO GP LLC and VIKING GLOBAL OPPORTUNITIES ILLIQUID INVESTMENTS SUB-MASTER LP,
pursuant to an authorization and designation letter dated February 9, 2021, which was previously filed with the Commission as
an exhibit to a Form 13G filed by Ms. Shabet on February 12, 2021 (SEC File No. 005-49737).